Everything you need to support STARTTLS (encrypted mail transmission and user authentication via certificates) is installed and configured but is *NOT* being used.

To enable sendmail to use STARTTLS, you need to: 1) Add this line to /etc/mail/sendmail.mc and optionally to /etc/mail/submit.mc: include(`/etc/mail/tls/starttls.m4')dnl 2) Run sendmailconfig 3) Restart sendmail